1. Field of the Invention
The present invention relates to a motor-driven steering apparatus.
2. Description of the Related Art
For a motor-driven steering apparatus for a saddle riding type vehicle such as a buggy vehicle or the like, there has been a structure in which a motor-driven steering assist unit is interposed between a steering shaft of a handle side and a wheel side steering member, as described in Japanese Patent Application Laid-open No. 2004-231011 (patent document 1). The structure is made such that a steering force applied to the handle by a driver is assisted by a generated torque of an electric motor.
A conventional motor-driven steering apparatus is structured such that a steering shaft in a handle side is attached to a position at a proper mounting angle with respect to an input shaft of a motor-driven steering assist unit, a wheel side steering member is attached to a position of a proper mounting angle with respect to an output shaft, and a motor-driven steering assist unit is thereafter attached to a vehicle body frame. At this time, if the mounting position of the motor-driven steering assist unit with respect to the vehicle body frame is deviated, a torsion bar coupling an input shaft and an output shaft of the motor-driven steering assist unit is ineffectively twisted, and it is impossible to set the mounting position of the handle to a proper neutral position.
However, in the prior art, the mounting position of the motor-driven steering assist unit with respect to the vehicle body frame is shifted from a correct position at a mounting state of the motor-driven steering assist unit to the vehicle body frame, and it is impossible to easily discriminate whether or not the torsion bar coupling the input shaft and the output shaft of the motor-driven steering assist unit is twisted ineffectively. Even if it is found after an assembly of the vehicle is finished that the actual mounting position of the handle is deviated from the proper neutral position, it is hard to correct the deviation because of the other auxiliary machines attached to the vehicle body frame.